Prepare the Potatoes: Remove the skins and finely shred the potatoes using a grater. Place them in a clean towel or cheesecloth, and squeeze out as much moisture as possible to ensure a crispy texture. Set aside.

Cook the Onion: In a large skillet, heat 1 tbsp oil over medium heat. Add the shredded onion and sauté until soft and golden, about 5 minutes. Remove from skillet and set aside.

Combine Ingredients: In a large mixing bowl, mix the grated potatoes with the cooked onion.

Fry the Rosti: In the same skillet, heat 1 tbsp butter and 1 tbsp oil over medium-high heat. Spread half of the potato mixture in an even layer, pressing it down with a spatula. Cook for 5-7 minutes on each side, until golden brown and crispy. Transfer to a plate and keep warm.

Add Bacon (Optional): If using, sprinkle chopped bacon over the finished rosti for added flavor.

Serve: Slice into wedges and serve hot. Enjoy the crispy, golden goodness!